[Effect of chlorpromazine on the incorporation of sialic acid into gangliosides and glycoproteins of the chicken brain (author's transl)].

Three-days-old White Leghorn chickens were used to study the effect of i.p.-injected chlorpromazine (CP, 2.5 or 5 mg/animal) on the incorporation of N-(3H)-acetylmannosamine into glycoprotein- and ganglioside-bound sialic acid and 14C-histidine into the proteins of the cerebrum, the optic lobes, and the cerebellum after incorporation periods of 1-24 h. All experiments were performed under constant temperature conditions. 1. The incorporation of 14C-histidine into the proteins of the optic lobes was not influenced by CP. 2. Within 24 h in the optic lobes neither the concentration of particle-bound sialic acid (mug sialic acid/mg protein) nor the content of radioactive-labeled sialic acid precursor was affected by the drug. 3. The rate of incorporation of labeled sialic acid into glycoproteins and gangliosides, however, was up to 6 h after the injection of the precursor much lower in the CP-treated animals than in controls. This may indicate, that the turnover of sialo-compounds was diminished by CP. 4. The inhibition was the most intensive in the cerebrum (up to 80%), lower in the optic lobes (up to 70%), and only small in the cerebellum (up to 20%), but was always the same for glycoproteins and gangliosides. The different inhibition rates in the different structures may indicate a correlation between the pharmacologic, sedative effects of the drug and the diminished turnover of sialo compounds.